Antioxidant and Antimicrobial Properties of Garlic as Affected by Nitrogen and Selenium Concentrations

Antibiotic resistance has contrived the use of medicinal plants with fewer side effects instead of common drugs. Garlic has sulfur-containing organic compounds and has broad antimicrobial properties against bacteria, even in the lowest concentrations. Allicin or diallyl disulfide is the main garlic sulfur compound with antimicrobial activity. This research investigated the different impacts of nitrogen (N) and selenium (Se) concentrations on garlic clove antioxidant and antibacterial activity. Three concentrations of Se, such as 0, 5, and 10 mg/l sodium selenate and N, containing 0, 50, 100, and 150 Kg/ha, were examined on garlic’s antioxidant and antimicrobial properties. The results showed that the antioxidant activity (66.77%) improved in four nitrogen concentrations. Selenium decreased the allicin content of garlic clove. The highest inhibition of the growth rate was observed in Escherichia coli at 12.00 mm, Pseudomonas aeruginosa at 1.73 mm, Bacillus subtilis at 8.95 mm, and Staphylococcus aureus at 10.90 mm were obtained in 150 kg/ha N coupled with 10 mg/l sodium selenate. The lowest inhibitor of the growth of all four bacteria was observed in the control treatment. According to the results, an increase in antioxidant activity was associated with an increase in the antimicrobial properties of garlic. The use of selenium and nitrogen increased the inhibitory influence of bacterial growth.